Type-writing machine.



PATENTED SEPT. 1, 1908.

APPLICATION FILED FEB. 8, 1908.

AttOTiZt? 1 Y TED srntwnnr ornrcn WILLIAM F. HELMOND, OF HARTFORD, CONNECTICUT, ASSIGNOR TO UNDERWOOD TYPE- I WRITER COMPANY, OF NEW YORK, Y., A CORPORATION OF NEW JERSEY.

TYPE-WRITING MACHINE rock arms.

' the parts being in normal positions.

Specification of Letters Patent.

Iatented Sept. 1, 1908.

Application filed. February 8, 1908. Serial No. 414,871.

roll mechanism.

I hang the front and rear pressure roll shafts upon rock arms, which are engaged by leaf springs to press the rolls against the platen; each spring being supported at its middle, and near each end engaging its The s rings are disposed opposite each other, an I arrange a key-operated rock shaft extending between said springs and parallel with the platen and having cams to engage thetips' of the springs. The described mechanism is mounted upon a sheet metal plate, which is secured at its ends to the ends of the platen frame, and has at its upper edge recesses to receive the rock arms; the latter mounted in pairs u on pivots or pintles which are attached to t e supporting p ate.

Other objects and advantages will hereinafter a pear.

In t e accompanying drawings, Figure 1 is a front elevation of the platen frame and platen of an Underwood typewriting machine, showing my improvements applied thFe reto;

i 2 is an inverted plan of a portion of the l ollreleasing mechanism at one end of the machine. Fig. 3 is an end elevation showing the release-key depressed,- and thepressure rolls mechanically eld away from the laten.

Fig. 4 is a view similar to Fig. 3, but s owing the parts in normal positions. F i 5 is a detail to illustrate the manner in w oh the roll-releasing rock-shaft is mounted upon the platen frame. Fig. 6 is a detail to be read in connection with Fig. 3, to show the action of the roll carrying-arms.

In said Underwood typewriting machine, a platen 1 is revolubly mounted in a platen rovide a simphfied, improved and cheapene pressure frame whose ends are seen at 2; the writing being done upon the front of the platen by type bars 3. Front and rear ressure rolls 4, 5 are arranged to run upon t e under side of the platen. Said rolls are carried upon shafts 6, 7, the front shaft carried in arms 8, and the rear shaft in arms 9, the shafts being detachable from the arms.

Springs 10, 11 arranged o posite each other, are secured at their mi dle ortions by screws 12, 13, and extend in eac direction along the platen, and near their free ends bear respectively upon fingers 14, 15, forme upon said arms 8, 9, respectively, to press the rolls against the platen. Said screws 12, 13

attach said springs to bracketslfi, 17, which are secured upon the front and rear faces of a main supportmg plate or bar 18, which is u v secured at its ends to the platen frame 61x65 2 1n any suitable manner. Said plate is recessed at its upper edge at 19 to receive the hubs of each of two pairs of arms 8, 9, said arms being pivoted, upon pintles 20 secured by screws 21 to the late, the'screws being transversely threade into said pintles, and each of the latter forming a bridge across the recess 19.

A release-key 22 upon the ri ht hand platen frame end is connected by a ink 23 to a crank 24 formed upon a rock shaft 25. The supporting-plate 18 is fluted at 26 to receive and form bearings for said rock shaft, the latter being retained by keepers 27 at the ends of the late. Upon said rock shaft are secured co ars 28 upon each of which is formed a double cam 29 to engage tips 30 turned in from the ends of the springs 10, 11, said cams operating when the finger-key 22 is depressed, to spread the. springs apart, Fig. 2, and release the fingers 14, 15, so that the rolls 4, 5 drop from the platen, Fig. 3. Each cam s formed upon its end with a flat or rest 31 to engage the tip of the s ring, and hold the latter mechanically in t e Fi 2 and 3 osition, when the key is depressed, so that the rolls are mechanically detained in released positions.

To regulate the tension of the s rings, screws 32 are employed, said screws aving heads 33 to engage one sprin and the shanks 5 of the screws being threade through theopscrew at either side of the brackets 16,17 the screws passing through openings 34 .in the plate 18.: 1

Having thus described my invention, I claim:

1. In a typewritin machine, the combination with a revolub e platen and a platen frame, of a releasable pressure-roll mechanism including a plate or bar. extending'along the platen and fixed at its ends to theends of the platen frame, a rock-shaft journaled upon said plate and extending along the platen, a key connected to said rock-shaft, cam collars upon said rock shaft, leaf 3 rings secured upon said late and eng'ageablb by said cam collars, an arms carrying pressure-rolls and engageable by said-springs and pivotedon said plate.

- 2; In a typewritin machine, the combina-' tion with a revolub e platen and a platen frame, of a releasable pressure-roll-.mechgagea the ends 0 journaled upon said, plate and extendin anism including a plate or bar extending along the platen and fixed atits ends to the platen frame, a rock-shaft along the p aten, a key connected to sai rock-shaft,cam collars upon said rock-shaft, leaf s ringssecured upon said late and enble by said cam collars, an arms oarr mg pressure-rolls and en ageable by said late; said arms upon said plate to carry each of sai pairs of arms.

85 nation with a revol 3.- In a typewriting machine, the combiu l e platen and aplaten frame, of a releasable pressure-roll mechanism including' a plate or bar extending'along the'platen and fixed at its ends to the ends of the platen frame, a rock-shaft journaled upon said plate and extendin along the platen, a key connected to sai rock-shaft, cam collars upon said rock-shaft, leaf springs secured uponsaid lateand engageable by gpressure-- said cam collars, an arms carr rolls and engageable by sai springs and pivoted on said plate; said plate havmgre cesses in its ed e'to receive the arms, and

said recesses bemg bridged by pintles upon which the arms are pivoted.

4. In a'typewriting machine, the combination with a revoluble platen and a platen frame, of a releasable pressure-roll mechanism including a plate or bar extending along the platen and fixed at its ends to the ends of the platen frame, a rock-shaft journaled:

upon said plate and extending along the platen, a key connected to said rock-shaft, cam collars upon said rock-shaft, leaf s rings secured upon said late and engagea le by said cam collars, and arms carrying pressurerolls and engageable by said springs and pivoted on said plate; each of said springs being secured at its middle portion to a bracket attached to the plate, one bracket upon each .5. In a typewriting machine, the combinaside of the plate, and the rock-shaft extending' between the springs.

tion with a revoluble platen and a platen frame, of a releasable pressure-roll mechanism including a plate or bar extending along the platen and fixed at its ends to the ends of the platen frame, a rock-shaft journaled .u on said plate and extending along the. p aten, a key connectedto said rock-shaft, cam collars upon said-rock-shaft, leaf s rings secured upon said plate and engagea le by said cam collars, and arms carrying pressurerolls and engageable by said springs and pivoted on said plate; each of said springs be,- ing secured at its middle portion to a bracket attached to the plate, one bracket upon each side of the plate, and the rock-shaft extending between the s rings; andvm'eans being provided to regu ate the tension of the springs, said regulatin means comprising screws each having a ead to enga e one spring and a shank threaded through t e opposite spring. a

' 6. In a typewriting machine, the combination with a revoluble platen and a platen frame, of a releasable pressure-roll mechan ism including a plate or bar extending along the platen and fixed at its ends to the ends of the platen frame, a rock-shaft journaled u on said .plate. and extending along thev p aten, a key connected to said rock-shaft, cam collars upon said rock-shaft, leaf s rings secured upon said late and engagea le by said cam collars, an arms can'yin'g pressurerolls and engageable by said springs and pivoted on said plate; said cam collars'provided with rests to engage the springs and hold them mechanically in released positions. =7. In a t ewriting'machine, th'ecombinatibn with a revoluble platen and a platen frame, of a releasable pressure-roll mechanism includin 'a rock-shaft, a key connected to said rock-s aft, cams upon said rock shaft 7 leaf springs engageable at their tips bvsai cams, and armscarrying pressure-r0 sand engageableby said s rlngs;v each of said springs being sup orte at its middle portion, one u on each si e of the rock-shaft. 8. a typewritin machine, the combination with a revolub e platen and a platen frame, of a releasable ressure-roll mechanism includin 'a rock-s aft, a key connected to said rock-s aft, cams upon said rock-shaft leaf springsengageable at their tips b said cams, and arms carrying pressure-r01 s and ng'ageable by said springs;x ,each v of said springs being sup orted at its middle portion,

a typewrltm machine, the combinav tion wlth a revolub e platen and a platen 139 l of rolls, arms carrying said rolls, a

frame, k

roc

each having a head to engage one spring and a shank threaded through the opposite spring.

'oneu on each slde 10. In a typewritingmachine, the combination with a revolub platen and a platen frame, of a releasable ressure-roll mechanism including a rock-s aft, a key connected to said rock-shaft, cams upon said rock-shaft, leaf springs engageable at their tips by said cams, and arms carrying pressure-rolls and engageable by said springs; each of said springs being supported at its middle portion, of the rock-shaft; said cams ormed on their ends with rests to engage the springs and hold them mechanically in released positions.

11. In a'typewritin machine, the combination with a revolub e platen and a platen frame, of pressure rolls to run upon the platen,-a key connected to a'rock-shaft, cams secured upon said rock-shaft, opposite leaf springs engageable by said cams an carrying said rolls and operabie by springs eacliof the springs being secured at its middle ortion upon a sup ort carried b the platen ame, and said roc -shaft exten ing along the platen between the springs.

12. In a typewriting machine, the-combination with a revolub e platen and a platen frame, of pressure rolls to run upon the platen, a key connected to a rock-shaft, cams secured upon said rack-shaft, opposite leaf springs engageable by said cams, and arms carrying said rolls and operable by said sprin s each'of the springs being secured at its mlddle ortion upon a sup ort carried by the platen ame, andsaidrog -shaft extend ing along the platen between the springs; and screws to regulate the tension of t springs, each screw engaging one spring and having a shank threaded through the opposite spring. V

WILLIAM FL'HELMOND. Witnesses:

W. M. BYORKMAN, MORTON O. TALoo'r'r.

6. arms said 

